diff --git a/core/attributedef/AttributeDBFieldVoid.php b/core/attributedef/AttributeDBFieldVoid.php
new file mode 100644
index 000000000..ac61a0d49
--- /dev/null
+++ b/core/attributedef/AttributeDBFieldVoid.php
@@ -0,0 +1,146 @@
+<?php
+
+/**
+ * Abstract class implementing default filters for a DB column
+ *
+ * @package     iTopORM
+ */
+class AttributeDBFieldVoid extends AttributeDefinition
+{
+    public static function ListExpectedParams()
+    {
+        return array_merge(parent::ListExpectedParams(), array("allowed_values", "depends_on", "sql"));
+    }
+
+    // To be overriden, used in GetSQLColumns
+    protected function GetSQLCol($bFullSpec = false)
+    {
+        return 'VARCHAR(255)'
+            . CMDBSource::GetSqlStringColumnDefinition()
+            . ($bFullSpec ? $this->GetSQLColSpec() : '');
+    }
+
+    protected function GetSQLColSpec()
+    {
+        $default = $this->ScalarToSQL($this->GetDefaultValue());
+        if (is_null($default)) {
+            $sRet = '';
+        } else {
+            if (is_numeric($default)) {
+                // Though it is a string in PHP, it will be considered as a numeric value in MySQL
+                // Then it must not be quoted here, to preserve the compatibility with the value returned by CMDBSource::GetFieldSpec
+                $sRet = " DEFAULT $default";
+            } else {
+                $sRet = " DEFAULT " . CMDBSource::Quote($default);
+            }
+        }
+
+        return $sRet;
+    }
+
+    public function GetEditClass()
+    {
+        return "String";
+    }
+
+    public function GetValuesDef()
+    {
+        return $this->Get("allowed_values");
+    }
+
+    public function GetPrerequisiteAttributes($sClass = null)
+    {
+        return $this->Get("depends_on");
+    }
+
+    public static function IsBasedOnDBColumns()
+    {
+        return true;
+    }
+
+    public static function IsScalar()
+    {
+        return true;
+    }
+
+    public function IsWritable()
+    {
+        return !$this->IsMagic();
+    }
+
+    public function GetSQLExpr()
+    {
+        return $this->Get("sql");
+    }
+
+    public function GetDefaultValue(DBObject $oHostObject = null)
+    {
+        return $this->MakeRealValue("", $oHostObject);
+    }
+
+    public function IsNullAllowed()
+    {
+        return false;
+    }
+
+    //
+    protected function ScalarToSQL($value)
+    {
+        return $value;
+    } // format value as a valuable SQL literal (quoted outside)
+
+    public function GetSQLExpressions($sPrefix = '')
+    {
+        $aColumns = array();
+        // Note: to optimize things, the existence of the attribute is determined by the existence of one column with an empty suffix
+        $aColumns[''] = $this->Get("sql");
+
+        return $aColumns;
+    }
+
+    public function FromSQLToValue($aCols, $sPrefix = '')
+    {
+        $value = $this->MakeRealValue($aCols[$sPrefix . ''], null);
+
+        return $value;
+    }
+
+    public function GetSQLValues($value)
+    {
+        $aValues = array();
+        $aValues[$this->Get("sql")] = $this->ScalarToSQL($value);
+
+        return $aValues;
+    }
+
+    public function GetSQLColumns($bFullSpec = false)
+    {
+        $aColumns = array();
+        $aColumns[$this->Get("sql")] = $this->GetSQLCol($bFullSpec);
+
+        return $aColumns;
+    }
+
+    public function GetBasicFilterOperators()
+    {
+        return array("=" => "equals", "!=" => "differs from");
+    }
+
+    public function GetBasicFilterLooseOperator()
+    {
+        return "=";
+    }
+
+    public function GetBasicFilterSQLExpr($sOpCode, $value)
+    {
+        $sQValue = CMDBSource::Quote($value);
+        switch ($sOpCode) {
+            case '!=':
+                return $this->GetSQLExpr() . " != $sQValue";
+                break;
+            case '=':
+            default:
+                return $this->GetSQLExpr() . " = $sQValue";
+        }
+    }
+}
\ No newline at end of file